Sorbent Pens™ (Pat. Pend.) For Next Generation Headspace Analysis

Sorbent Pens for Next Generation Headspace Analysis

Significance of the Topic

Headspace extraction plays a vital role in environmental, food, clinical and consumer product testing by enabling sensitive detection of volatile (VOCs) and semi-volatile compounds (SVOCs). Advances in sorbent materials and extraction design directly impact analytical sensitivity, reproducibility and laboratory throughput.

Objectives and Overview of the Study

This technology overview introduces Entech’s Sorbent Pens™ and Vacuum Assisted Sorbent Extraction (VASE) as a versatile headspace sampling approach. Key goals are to compare performance with established techniques such as SPME and dynamic headspace trapping, demonstrate reproducibility, and highlight applications across water analysis, flavors, cannabinoids, clinical markers and more.

Methodology and Instrumentation

Extraction is performed by placing a Sorbent Pen under reduced pressure within a sample vial to accelerate diffusion and achieve near-equilibrium adsorption of analytes. After offline extraction (ranging from minutes to days), pens are thermally desorbed directly into a GC column. Instrumentation includes:

• 5800 Sorbent Pen™ Desorption Unit (SPDU) with Silonite™ coated flow path
• Vacuum generation via Micro-QT™ valves and oilless diaphragm pumps
• Optional 5600 Extraction System for automated agitation and temperature control
• Sample Preparation Rail (SPR) for high-throughput handling of up to 120 pens
• GC-MS platforms (Agilent 7890B/5977A, Thermo or Shimadzu equivalents)

Main Results and Discussion

Sorbent Pens operating in VASE mode deliver higher recoveries (60–98%) and improved run-to-run precision (2–5% variation) compared to SPME (2–20%, highly variable). The vacuum-enhanced diffusion overcomes limitations of diffusion at atmospheric pressure, allowing efficient sampling of both low- and high-volatility compounds. Kinetic studies in water matrices demonstrate that equilibrium is reached within hours and quantitative extraction is maintained for compounds such as geosmin and tribromoanisole.

Benefits and Practical Applications

Key advantages include:

• Wide volatility range coverage for VOCs and SVOCs
• Minimal carryover without secondary bake-out steps
• Rapid, cryogen-free injections for better chromatography
• High throughput via offline, parallel extraction
• Robustness with hundreds of reuses per pen

Applications span EPA 8270 wastewater analysis, food flavor profiling, clinical breath and urine markers, pesticide screening in cannabis, and odor testing in consumer goods.

Future Trends and Potential Applications

Integration with laboratory automation will drive productivity gains. Further material innovations may extend sorbent selectivity for challenging analytes such as polar compounds and emerging contaminants. Coupling VASE with two-dimensional GC or high-resolution MS promises enhanced separation and identification capabilities.

Conclusion

Entech’s Sorbent Pens and VASE technique represent a quantitative-by-design approach for headspace analysis, offering a compelling alternative to traditional methods. The combination of vacuum-enhanced extraction, durable sorbent format, and direct desorption yields superior sensitivity, reproducibility and throughput, addressing critical needs in environmental, food, clinical and industrial laboratories.